Commercially available cameras are adapted for use with various accessories, including a power winder for controlling the advance of film within the camera inde-pendently of the manually actuated device for that purpose provided on the camera itself. More particularly, such cameras have an extra shutter releasing socket, a film winding socket and power contacts located on the body of the camera which operatively interrelate with the winder when the latter is secured to the camera.
A power winder typically includes a shutter release button which controls a switch for completing a circuit to a solenoid which in turn functions to move a pin from within the winder into the camera's shutter releasing socket to thereby operate the shutter. The motor of the winder then actuates a mechanical arrangement which extends into the film winding socket so that the film is advanced.
The use of a solenoid in controlling the operation of the winder's shutter release pin represents an expensive component of the power winder. The present invention provides a more economical version of such a device in which the solenoid is eliminated and an improved power winding mechanism is provided.